A memory device having a three-dimensional structure has been proposed in which a memory hole is formed in a stacked body in which electrode layers are stacked with insulating layers interposed therebetween, the electrode layers functioning as a control gate in a memory cell, and in which a silicon body is provided in a side wall of the memory hole, the silicon body becoming a channel with a charge storage film interposed therebetween.
With respect to the stacked body, including the plurality of electrode layers and the plurality of insulating layers, provided in this type of three-dimensional device, a memory hole or a slit is formed using a reactive ion etching (RIE) method, for example. At this time, as a number of layers in the stacked body increases, higher shape controllability and dimensional controllability are required for the etching operation.